TD-SCDMA (Time Division Synchronized Code Division Multiple Access) is a wireless communication standard that combines TDD/TDMA (Time Division Duplexing/Time Division Multiple Access) operation with synchronous CDMA (Code Division Multiple Access). TD-SCDMA can assign users to different time slots and spreading codes, whereby each time slot can contain data associated with different users distinguished by a distinct spreading code. FIG. 1 illustrates a TD-SCDMA scheme 100 wherein a frequency band 110 may be used for communication associated with multiple users via the assignment of users to different time slots 121, 122, 123, 124, etc. and different spreading codes 1, 2, 3, etc. (e.g., up to 16 spreading codes may be utilized by a TD-SCDMA slot). Current TD-SCDMA utilizes up to 16 spreading codes per time slot, such that a maximum of 16 users may be simultaneously allocated different spreading codes in a given time slot. In some instances, a user may be allocated to multiple spreading codes.
TD-SCDMA supports asymmetric traffic and services, whereby uplink and downlink traffic allocations are modified using a flexible frame structure that enables uplink and downlink allocations to be dynamically modified during a call. TD-SCDMA also allows for multiple access interference (MAI) to be reduced using joint detection and smart antenna systems. In a joint detection scheme, data from multiple users that may be associated with a time slot are estimated in parallel and a specific user's data is extracted from a received signal. In this way, interference due to signals associated with other users is accounted for and data provided to a user can exhibit reduced interference.